Process for removing the halphen test response from alkali refined cottonseed oil



United States Patent PROCESS FOR REMOVING THE HALPHEN TEST RESPONSE FROMALKALI REFINED COTTON- SEED OIL Eric T. Rayner and Harold P. Dupuy, NewOrleans, La.,

assignors to the United States of America as represented by theSecretary of Agriculture No Drawing. Filed Dec. 2, 1963, Ser. No.327,560

3 Claims. (Cl. 260-424) A non-exclusive, irrevocable, royalty-freelicense in the invention herein described, throughout the world for allpurposes of the United States Government, with the power to grantsublicenses for such purposes, is hereby granted to the Government ofthe United States of America.

This invention relates to a process for removing the Halphen testresponse from (alkali refined) cottonseed oil and has as its object theproduction of cottonseed oils that react negatively to the Halphen test.

Cottonseed oil, in addition to the major fatty acid constituents, isreported to contain from a fraction of one percent to about two percentof malvalic acid. Malvalic acid reacts positively to the so-calledHalphen test. Cottonseed oil also reacts positively to the Halphen testas do the seed oils of many malvaceous plants.

It is known that acids containing the cyclopropene ring (i.e., malvalicand sterculic acids), when included in the rations of laying hens, arecapable of producing certain abnormalities, such as pink egg whites,salmon colored, enlarged, fluid yolks, and reduced hatchability. Inaddition, it has been reported that a correlation exists between theintensity of the Halphen test as applied to the residual oil in thecottonseed meal component of a poultry ration and the occurrence ofabnormalities in stored intact eggs.

Prolonged heating of cottonseed oil has been reported to eliminate theHalphen test response but this is not practical for cottonseed oil, theintended end use for which is an edible use, since prolonged heating ofvegetable oils in the presence of air is known to produce toxicpolymers.

Certain halogen containing mineral acids are also reported to effect areduction of or the destruction of Halphen test response, but theaddition of such extraneous halogenated materials tocyclopropenoid-containing edible oils is per se most undesirable.

In general, the process of our invention which We use to eliminate theHalphen test response from cottonseed oil comprises treating apreviously alkali refined oil with at least about four equivalents,based on the cyclopropene acid content of the oil, of certain naturallyoccurring monobasic fatty acids of vegetable origin, such as capric acidor cottonseed fatty acids, and employing therewith a temperature of upto 235 C. for an interval of about two hours to completely eliminate theHalphen test response. This heat treatment, conducted under inertatmosphere in a standard deodorizing flask, is followed by aconventional deodorization procedure, as by heating under vacuum,carried out at 235 C. for a period of about one hour. The deodorizationprocess functions not only to remove remaining odors and flavors fromthe oil, but additionally reduces the acid content of the oil to belowthat of the original alkali refined oil used as starting material.Although capric acid and cottonseed fatty acids are equally efficaciousin eliminating the Halphen test response from cottonseed oil when usedaccording to the methods set forth in this invention; it is, however,our opinion that the use of the lower molecular weight and lower boilingcapric acid may ofier an advantage with respect to ease of removal fromthe oil. Use of capric acid should permit lower deodorizationtemperatures for shorter periods of time.

As will be appreciated by those versed in the art of vegetable oilrefining, the heating of crude oil at even the relatively lowtemperatures required by our process tends to fix the naturallyoccurring color bodies and make diflicult the production of a finishedoil with acceptable color characteristics. The use, however, of alkalirefined oil in our process of Halphen test response inactivationcircumvents completely the color problems which might otherwise arise inusing crude cottonseed oil.

Thus our invention comprises a simple two-step process for Halphen testresponse inactivation which is suitable for commercial use, utilizingconventional procedures and existing processing equipment.

While specific reaction times, reaction temperatures, and acidconcentrations have been outlined in our examples, they are not to beconstrued as the only operable combinations for effectively eliminatingthe Halphen test response from alkali refined cottonseed oil. Byincreasing acid concentrations lower temperatures and reduced reactiontimes may be employed. Similarly, an increase in the variables of timeand temperature would allow the use of reduced acid concentrations.

It is our opinion that the carboxyl group of the fatty acid we employreacts with the material responsible for Halphen test response thusrendering it inactive. Although we are by no means certain that this isthe mechanism of our process, inability to explain the reaction in noway detracts from the etficacy of the process. We are able todemonstrate by chemical test the complete elimination of Halphen testresponse in cottonseed oils treated by our process.

The A.O.C.S. Halphen test, Ofiicial Method Cb 1-25, was used formeasuring Halphen test response in our examples which follow:

Examples Portions of alkali refined cottonseed oil were heated undernitrogen at 235 C. for two-hour intervals with four equivalents, basedon cyclopropene acid content of the oil, of capric acid or cottonseedfatty acids. Immediately following this heat treatment the oils weredeodorized at 235 C. for one hour, employing conventional deodorizingmethods. The resulting oils were then tested for the Halphen testresponse. Some selected data from the manifold experiments which weperformed for the purpose of establishing optimum operating limitationsfor our method are shown in tabular form in Table I.

TABLE I [The treatment of alkali refined cottonseed oil with monobasicfatty acids to eliminate the Halphen test response] Concentration HeatTreatment Acid Value 3 Halphen Acid Test 4 Percent (M) Eqv. C. Hrs.Original Deodorized Oil Oil 1 Equivalents based on 0.63% cyclopropenoidcontent expressed as malvalic acid. 2 Hours of heating in all casesconsisted of two hours under inert gas at atmospheric pressure followedby one hour of vacuum deodorization.

3 Determined by A.O.C.S. Halphen Test, Oificial Method Cb 125.

4 This oil was heated one hour at 235 0., but deodorized at only 200 fortwo hours.

5 Expressed as percent oleic acid.

Having thus described our invention, We claim: 1. A process foreliminating Halphen test response in alkali refined cottonseed oilcomprising (a) treating the alkali refined cottonseed oil in an inertatmosphere at a temperature of 235 C. for a period of about two hourswith at least about four equivalents, based on the cyclopropene acidcontent of the oil, of capric acid, and (b) deodorizing by heating undervacuum at 235 C. for an'additional period of about one hour the oilobtained in Step (a) above. 2. A process for eliminating Halphen testresponse in alkali refined cottonseed oil comprising (a) treating thealkali refined cottonseed oil in an inert atmosphere at a temperature of235 C. for a period of about two hours with at least about fourequivalents, based on the cyclopropene acid content of the oil, ofcottonseed fatty acids, and (b) deodorizing by heating under vacuum at235 C.

for an additional period of about one hour the oil obtained in Step (a)above. 3. A process for eliminating Halphen test response in 5 alkalirefined cottonseed oil comprising of capric acid and cottonseed fattyacids, and

(b) deodorizing by heating under vacuum at 235 C. for an additionalperiod of about one hour the oil obtained in Step (a) above.

No references cited.

ALEX MAZEL, Primary Examiner. ANTON H. SUTTO, ANNE MARIE TIGHE,

Assistant Examiners.

3. A PROCESS FOR ELIMINATING HALPHEN TEST RESPONSE IN ALKALI REFINEDCOTTONSEED OIL COMPRISING (A) TREATING THE ALKALI REFINED COTTONSEED OILIN AN INERT ATMOSPHERE AT A TEMPERATURE OF 235*C. FOR A PERIOD OF ABOUTTWO HOURS WITH AT LEAST ABOUT FOUR EQUIVALENTS, BASED ON THECYCLOPROPENE ACID CONTENT OF THE OIL, OF A MEMBER SELECTED FROM THEGROUP CONSISTING OF CARPIC ACID AND COTTONSEED FATTY ACIDS, AND (B)DEODORIZING BY HEATING UNDER VACUUM AT 235*C. FOR AN ADDITIONAL PERIODOF ABOUT ONE HOUR THE OIL OBTAINED IN STEP (A) ABOVE.